Mitral valve replacement Starr-Edwards cloth-covered composite-seat prosthesis

Late re-operation for aortic and mitral Starr-Edwards ball valve prostheses

Starr-Edwards ball valves removed more than 15 years after implantation were retrospectively investigated macroscopically. Eight patients required re-operation. Valve models used in the initial operations were a non-cloth-covered valve in 2 patients and a cloth-covered valve in 6. Two patients had replacement of an aortic ball valve (model 1260 and model 2320) and 6 underwent mitral valve replacement (model 6120 in one, model 6320 in 5). The mean time to re-operation was 23.0 +/- 4.8 years after implantation. Cloth wear causing significant hemolysis was observed in all cloth-covered valves, regardless of valve position. Autologous tissue growth was noted on the orifice ring and struts in both aortic and mitral prostheses. Thrombus formation was not found in any of the valves. Ball variance in silicone rubber balls was mild in the non-cloth-covered valves, even in the aortic position. The most significant problem with the cloth-covered ball valve was cloth wear. Cloth wear should always be considered when 15 years or more have passed since valve implantation. Significant hemolysis, elevation of lactate dehydrogenase values, and echocardiographic detection of transvalvular regurgitation are diagnostic of cloth wear, and are indications for replacement of a cloth-covered ball valve.

Surgical pathology and etiology of 278 surgically removed mitral valves with pure regurgitation in Thailand

INTRODUCTION

There are multiple causes of mitral regurgitation. Its etiology includes floppy valve, postinflammatory disease, infective endocarditis, and other disorders. Recently, there has been an increased tendency to remove only portions of the mitral valve, causing difficulty in the determination of etiology. Our objective was to study the pathology and etiology of mitral regurgitation from surgically removed specimens.

METHODS

Native mitral valve specimens surgically excised due to mitral insufficiency were examined. Etiology was determined according to macroscopic, microscopic, clinical, and operative findings.

RESULTS

Among 278 mitral valve specimens, 43% were classified as floppy valve, 31% as postinflammatory disease (presumably associated with rheumatic fever), 12% as infective endocarditis, and 14% as miscellaneous group. In floppy valves, diffuse myxoid change and chordal rupture were the main findings. In postinflammatory disease, moderate neovascularization and chronic inflammatory cell infiltration were most commonly found. Aschoff bodies were found in two cases. In infective endocarditis, gram-positive cocci were found in 70% of cases. In the miscellaneous group, three cases were related to Marfan syndrome and one case was related to papillary muscle necrosis. In comparison with postinflammatory disease, the posterior leaflet in the floppy valve had a significantly longer basal free-edge length, a more frequent chordal rupture, and an higher mean age of patients. Among completely and partially excised specimens with postinflammatory disease, there were no significant differences in microscopic findings.

CONCLUSION

The three most common etiologies in mitral regurgitation were floppy valve, postinflammatory disease, and infective endocarditis. Macroscopic, microscopic, clinical, and operative findings are important in the evaluation of etiology, especially in partially excised specimens.

Pathology of mitral valve stenosis and pure mitral regurgitation--Part II

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant mitral valves. In Part I, conditions producing mitral valve stenosis were reviewed. In over 99% of stenotic mitral valves, the etiology is rheumatic disease. Other rare causes of mitral stenosis include congenitally malformed valves, active infective endocarditis, massive annular calcium, and metabolic or enzymatic abnormalities. In Part II, conditions producing pure mitral regurgitation are discussed. In contrast to the few causes of mitral stenosis, the causes of pure (no element of stenosis) mitral regurgitation are multiple. Some of the conditions producing pure regurgitation include floppy mitral valves, infective endocarditis, papillary muscle dysfunction, rheumatic disease, and ruptured chordae tendineae.

Pathology of mitral valve stenosis and pure mitral regurgitation--Part I

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant mitral valves. In Part I, conditions producing mitral valve stenosis are reviewed. In over 99% of stenotic mitral valves, the etiology is rheumatic disease. Other rare causes of mitral stenosis include congenital malformed valves, active infective endocarditis, massive annular calcium, and metabolic or enzymatic abnormalities. In Part II, conditions producing pure mitral regurgitation will be discussed. In contrast to the few causes of mitral stenosis, the causes of pure (no element of stenosis) mitral regurgitation are multiple. Some of the conditions producing pure regurgitation include floppy mitral valves, infective endocarditis, papillary muscle dysfunction, rheumatic disease, and ruptured chordae tendinae.

Surgical pathology of the mitral valve: a study of 712 cases spanning 21 years

The gross surgical pathologic features of the mitral valve were reviewed in 712 patients who had undergone mitral valve replacement at our institution during 1965, 1970, 1975, 1980, and 1985. Among the 452 cases of mitral stenosis, either with or without mitral insufficiency, 99% were attributable to postinflammatory disease and 1% were related to congenital mitral stenosis. Among the 260 cases of pure mitral regurgitation, the two most common causes were a floppy valve (38%) and postinflammatory disease (31%). Moreover, a floppy valve was observed in 73% of the 59 examples of chordal rupture and in 38% of the 16 cases of infective endocarditis. Women accounted for 73% of the 452 cases of mitral stenosis and for 72% of the 530 cases of postinflammatory disease. In contrast, men accounted for 58% of the 260 cases of pure mitral regurgitation, including 76% of the floppy valves and 69% of the infected valves. During the 21 years spanned by the study, the relative frequency of postinflammatory mitral insufficiency progressively decreased, whereas that of floppy mitral valves increased. It is unclear whether aging, heredity, environmental factors, changes in the frequency of acute rheumatic fever, or changes in patient referral practices may account for this observation.

Prosthetic heart valves: a review

There are a number of difficulties inherent in the analysis of such a large and diverse quantity of data. In a substantial number of clinical trials, there is no significant effort made to evaluate prosthetic performance as a function of preoperative cardiac anatomy. Hemodynamics have not been systematically studied in relation to preexisting left ventricular size, shape, or configuration, mitral annular orientation, or left atrial size. Postoperative anticoagulation protocols vary from one institution to another and occasionally within study groups themselves. Less tangible variables such as alteration in surgical technique over time and differential familiarity of cardiovascular surgeons with the prostheses employed are chronic problems in any study of this sort. Perhaps the greatest variable in evaluating the postoperative performance of valvular prostheses over the past 20 yr is the radical improvement in techniques of intraoperative myocardial preservation. Notwithstanding, comparisons are possible within the confines of certain criteria. The caged ball value remains in use after 20 years of clinical experience. It has sustained the greatest number of modifications, probably because it has been the most extensively studied. Hemodynamics are adequate although its centrally obstructed design is responsible for increased turbulence, hemolysis, and neointimal proliferation, particularly in the aortic position. The device has been shown to be durable with virtually no reports of ball variance since the alteration of the silicone curing procedure in 1965. Thromboembolic rates are acceptable in the anticoagulated patient while prosthetic thrombosis is not a grave threat in the non-close clearance device. Incidence of endocarditis is not particularly different from that associated with all nonbioprosthetic valves, although there is a much greater published volume of clinical experience concerning recognition and treatment of late prosthetic valve endocarditis in patients with caged ball valves than there is for any other replacement device. Perhaps the most serious disadvantage to caged ball design is its size. Its large spatial requirements have led to anatomic complications in patients with small aortic roots, isolated mitral stenosis, left ventricular hypertrophy, and double valve replacement, among others. Nevertheless, this is still the valve of choice in some centers.(ABSTRACT TRUNCATED AT 400 WORDS)

Treatment of infective endocarditis: a 10-year comparative analysis

The results of surgical and non-surgical treatment of active infective endocarditis in 182 patients over a 10-year period were analyzed. Heart failure, annular and myocardial abscesses, heart block, and coronary embolism, seen most frequently with staphylococcal and fungal endocarditis, were the primary causes of death in both native valve endocarditis (NVE) and prosthetic valve endocarditis (PVE). In NVE, surgery significantly improved the survival in patients with moderate or severe heart failure (P less than 0.05) and in all patients with staphylococcal endocarditis (P less than 0.03). In PVE, surgery significantly influenced survival in patients with moderate or severe heart failure (P less than 0.05) and in the entire group with late PVE (P less than 0.01). Early surgery is recommended for patients with native valve endocarditis and moderate or severe heart failure; those patients with staphylococcal NVE, regardless of hemodynamic state, should undergo early valve replacement. Early surgery is recommended for PVE patients with moderate or severe heart failure. We also recommend early valve replacement for early and late staphylococcal PVE.

Complications due to cloth wear in cloth-covered Starr-Edwards aortic and mitral valve prostheses--and their management

Five cases of complications due to cloth wear in cloth-covered composite-seat Starr-Edwards aortic and mitral valvular prostheses are described. The complications of cloth wear were recurrent systemic emboli in three patients, two with aortic and one with mitral prosthesis, and severe hemolytic anemia in two patients with aortic prosthesis. The over-all incidence of clinically significant complications due to cloth wear in aortic and mitral valve prosthesis was 2.5 per cent. The diagnosis of cloth wear is impossible before reoperation and it was made by exclusion of other causes of recurrent transient cerebral ischemic attacks or systemic emboli and by exclusion of other causes of hemolytic anemia. Clinical and laboratory findings suggestive of cloth wear are described. Aggressive management of complications of cloth wear by reoperation is likely to prevent disabling or lethal consequences. Porcine xenograft aortic and mitral bioprostheses were used in these patients to replace the cloth-covered valvular prostheses. The symptoms due to cloth wear were abolished in all patients by reoperation, and all patients are off anticoagulants postoperatively. The operative mortality rate for reoperation in this small group of patients was zero.

The determinants of survival following reoperation on prosthetic cardiac valves

In an effort to identify the determinants of survival following reoperation on patients with prosthetic cardiac valves, the experience with a group of 33 patients at the University of Rochester Medical Center was reviewed. The survival rate was 58% (19/33). Survival was not related to the valve involved, the age of the patient, or the technical hazards of a second cardiac operation. Ten (77%) of the 13 patients in New York Heart Association (NYHA) Functional Class II survived compared with 8 (40%) of the 20 in Class III or IV. The survival rate for patients with a paravalvular fistula was 79% (11/14); with valve dysfunction, 50% (6/12); and with prosthetic valve infection, 29% (2/7). The determinants of survival seem to be similar to those for primary operation (i. e., NYHA patient classification and indication for operation) and less related to the potential operative complications of a reoperation.

Long-term results in 1375 patients undergoing valve replacement with the Starr-Edwards cloth-covered steel ball prosthesis

The two principal considerations with prosthetic valves are durability and thromboembolism. With the widespread interest in recently developed prosthetic valves (porcine, tilting disc, Cooley), the long-term results at one institution with a single prosthesis were considered of particular importance. Accordingly, a 97% follow-up has been completed on 1375 patients (pts) undergoing prosthetic valve replacement with the Starr-Edwards cloth-covered steel ball prosthesis at New York University between October 1967 and December 1975. Operative procedures were as follows: aortic valve replacement (AVR): 470 pts; mitral valve replacement (MVR): 362 pts; combined AVR and MVR: 129 pts; other combined procedures: 414 pts. Overall operative deaths were 13.7%, 9% for AVR, 10.8% for MVR, and 18.6% for combined AVR and MVR. At seven years, AVR survival was 64%, and MVR survival 64.5%. There has been widespread pessimism, usually without significant data, about the cloth-covered prosthesis, because of concern of cloth wear, hemolysis and other complications. Therefore, a particularly significant finding by actuarial analysis was that 85% of surviving patients with isolated AVR remained free of emboli for five years. In pts surviving isolated MVR, 80% remained free of emboli for five years. Of those having embolic episodes, 33% were not on anticoagulants. Fatal hemorrhage from anticoagulants occurred in 0.8% of pts. Endocarditis occurred in 5.7% of the entire group, with 1.3% requiring reoperation. Clinically significant hemolysis occurred in 5.1% of the group, with only 0.2% requiring reoperation. Hence, the total frequency of clinically significant cloth-wear was less than 0.5%. These data indicate both the reliability and the limitations of the Starr-Edwards cloth-covered steel ball valve and can be used in comparing experiences with the more recently developed prostheses.

Mitral valve replacement with the modified University of Cape Town (UCT) prosthesis: clinical and hemodynamic results

Mitral valve replacement with the modified University of Cape Town prosthesis was performed in 42 patients. In 35 the procedure was an isolated one, and the hospital mortality was 6%. The late survival rate was 60%, half of the late deaths being the result of thromboembolism or complications of anticoagulant therapy. The incidence of hemolysis was low, and hemodynamic results demonstrated improvement in cardiac index and lowering of pulmonary artery pressure, pulmonary artery wedge pressure, pulmonary arteriolar resistance, and transvalvular mean gradients. However, the calculated prosthetic valve orifice area was lower than the measured area. Because of complications of thromboembolism, the high incidence of late deaths, and high transvalvular gradients, this prosthetic valve is no longer used in patients requiring mitral valve replacement.

Combined valvular and coronary artery surgery

Between July 1, 1971, and March 1, 1975, 45 patients underwent combined valvular and coronary artery operation. Aortic valve disease was present in 30 patients, mitral valve disease in 13, aortic and mitral valve disease in 1, and tricuspid valve disease in 1. The average age was 57 years. Seventeen patients were in New York Heart Association Functional Class IV. Seventeen patients had had a previous myocardial infarction. Significant coronary artery disease was an unexpected finding at the time of coronary angiography in 14 patients. The average number of grafts inserted was 2.5 per patient. The grafts were placed prior to valve replacement, and periods of myocardial ischemia were kept at a minimum by maintaining coronary perfusion throughout the operation. Operative mortality was 16%; late mortality was 8%. Perioperative myocardial infarction occurred in 2 patients.

Late clinical problems with Beall model 103 and 104 mitral valve prostheses: hemolysis and valve wear

The purpose of this study was to determine the influence on hemolysis of the spatial orientation of the struts in the Beall mitral valve prosthesis, Models 103 and 104. Thirteen pairs of patients were selected to match struts oriented parallel and perpendicular to the left ventricular outflow tract axis. The average time after operation was 3.73 years. Complete blood counts and relative serum chemistry values were determined.

Early risks of open heart surgery for mitral valve disease

During 1972 and 1973, a total of 235 patients had open heart surgery for mitral valve disease unassociated with significant aortic or rheumatic tricuspid valve disease. Thirty-one underwent closed heart mitral commissurotomy, without mortality. Of the 204 patients undergoing open operation, 125 had sequential measurement of cardiac output and mixed venous oxygen pressure. The hospital mortality rate was 6.4 percent in the larger group of 204 patients and in the 125 with cardiac output measurements. The rate was greater in those with class IV disability (New York Heart Association criteria) preoperatively than in those with class III or II disability. The mean +/- standard deviation of the average cardiac index early postoperatively was 2.05 +/- 0.579 liters-min--1-m--2. Cardiac index was lower in the patients who died early postoperatively than in those who did not. The probability of hospital death was a significant function of cardiac index. The predicted probability of death was 10 percent with an average cardiac index of 1.42 liters-min--1-m--2 and increased sharply with lower indexes. Cardiac index was lower early postoperatively than preoperatively, and was lower in patients in class IV than in those in class III. There was no significant difference in cardiac index between patients with mitral valve replacement and those in repair. A history of closed commissurotomy, age, duration of cardiopulmonary bypass, duration of cardiac ischemia and method of myocardial preservation did not significantly influence cardiac index or hospital mortality rate. There was no significant relation between mixed venous oxygen pressure and hospital death. Further improvement in results of mitral valve surgery requires adequate preservation of left ventricular performance before, during and after operation.